Rotavirus vaccine

Rotavirus vaccine

Vaccine description
Target disease	rotavirus
Type	Attenuated virus
Clinical data
AHFS/Drugs.com	monograph
MedlinePlus	a607024
Pregnancy category	US: C
Routes of administration	by mouth
Identifiers
ATC code	J07BH02 (WHO)
NY (what is this?)  (verify)

Rotavirus vaccine is a vaccine used to protect against rotavirus infections. These viruses are the leading cause of severe diarrhea among young children. The vaccines prevent 15 to 34% of severe diarrhea in the developing world and 37 to 96% of severe diarrhea in the developed world. The vaccines appear to decrease the risk of death among young children due to diarrhea. Immunizing babies appears to decrease rates of disease among older people and those who have not been immunized.

The World Health Organization (WHO) recommended that rotavirus vaccine be included in routine vaccinations especially in areas where the disease is common. This should be done along with promoting breastfeeding, handwashing, clean water and good sanitation. It is given by mouth and requires two or three doses. It should be given starting around six weeks of age.

Safety of the vaccines are good. This includes in people with HIV/AIDS. A prior version of the vaccine was linked to intussusception, but the current versions are not clearly linked. Due to a potential risk they are not recommended in babies who have had intussusception. The vaccines are made from weakened rotavirus.

The vaccine first became available in the United States in 2006. It is on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system. The wholesale cost is between 6.96 and 20.66 USD per dose as of 2014. In the United States it is more than 200 USD. As of 2013 there are two types of vaccine available globally, Rotarix and RotaTeq, with a number of others available in certain countries.

Medical uses

Effectiveness

A 2009 review estimated that vaccination against rotavirus would prevent about 45% of deaths due to rotavirus gastroenteritis, or about 228,000 deaths annually worldwide. At $5 per dose the estimated cost per life saved was $3,015, $9,951 and $11,296 in low-, lower-middle-, and upper-middle-income countries, respectively.

Safety and efficacy trials in Africa and Asia found that the vaccines dramatically reduced severe disease among infants in developing countries, where a majority of rotavirus-related deaths occur. A 2012 Cochrane review concluded that they are effective vaccines.

Rotavirus vaccines are licensed in more than 100 countries, but only 31 countries have introduced routine rotavirus vaccination as of 2011. The incidence and severity of rotavirus infections has declined significantly in countries that have acted on the recommendation to introduce the rotavirus vaccine. In Mexico, which in 2006 was among the first countries in the world to introduce rotavirus vaccine, the diarrheal disease death rates from rotavirus dropped by more than 65% among children age two and under during the 2009 rotavirus season . In Nicaragua, which in 2006 became the first developing country to introduce the rotavirus vaccine, investigators recorded a substantial impact, with rotavirus vaccine preventing 60% of cases against severe rotavirus and cutting emergency room visits in half. In the United States, vaccination has reduced rotavirus-related hospitalizations by as much as 86% since 2006. The vaccines may also prevent illness in non-vaccinated children by limiting exposure through the number of circulating infections. In September 2013, the vaccine will be offered to all children in the UK, aged between two and three months, and it is expected to halve the cases of severe infection and reduce the number of children admitted to hospital because of the infection by 70 percent.

Schedule

The World Health Organization recommends the vaccine be given right after 6 weeks of age. Two or three doses more than a month apart should be given. It is not needed after two years of age.

Types

Rotarix

Rotarix is a monovalent, human, live attenuated rotavirus vaccine containing one rotavirus strain of G1P[8] specificity. ROTARIX is indicated for the prevention of rotavirus gastroenteritis caused by G1 and non-G1 types (G3, G4, and G9) when administered as a 2-dose series in infants and children. It was approved by the U.S. FDA in April 2008

RotaTeq

File:Clark-Offit-rotavirus-inventors.jpeg

H. Fred Clark and Paul Offit, the inventors of RotaTeq.

RotaTeq is a live, oral pentavalent vaccine that contains five rotavirus strains produced by reassortment. The rotavirus A parent strains of the reassortants were isolated from human and bovine hosts. Four reassortant rotaviruses express one of the outer capsid, VP7, proteins (serotypes G1, G2, G3, or G4) from the human rotavirus parent strain and the attachment protein VP4 (type P7) from the bovine rotavirus parent strain. The fifth reassortant virus expresses the attachment protein VP4, (type P1A), from the human rotavirus parent strain and the outer capsid protein VP7 (serotype G6) from the bovine rotavirus parent strain. In February 2006, the U.S. Food and Drug Administration approved RotaTeq for use in the United States. In August 2006, Health Canada approved RotaTeq for use in Canada. Merck is working with a range of partners including governmental and non-governmental organisations to develop and implement mechanisms for providing access to this vaccine in the developing world.

History

In 1998, a rotavirus vaccine (RotaShield, by Wyeth) was licensed for use in the United States. Clinical trials in the United States, Finland, and Venezuela had found it to be 80 to 100% effective at preventing severe diarrhea caused by rotavirus A, and researchers had detected no statistically significant serious adverse effects. The manufacturer of the vaccine, however, withdrew it from the market in 1999, after it was discovered that the vaccine may have contributed to an increased risk for intussusception, or bowel obstruction, in one of every 12,000 vaccinated infants. There then followed eight years of delay until rival manufacturers were able to introduce new vaccines which were shown to be more safe and effective in children: Rotarix by GlaxoSmithKline and RotaTeq by Merck. Both are taken orally and contain disabled live virus.

The experience, however, provoked debate about the relative risks and benefits of a rotavirus vaccine. This is because rotavirus is responsible for 29% of deaths from diarrhea in children below 5 years worldwide, and thus 4.2 million deaths could be avoided during that 8 years in different parts of the world. Meanwhile, other countries such as Brazil and Mexico undertook their own independent epidemiological studies which demonstrated that 4 deaths were attributable to vaccine, while it had prevented approximately 80,000 hospitalization and 1300 deaths from diarrhea each year in their countries. This example shed light on the importance of careful country-specific epidemiology, which enables rational balancing between benefit and risk.

Society and culture

The Rotavirus Vaccine Program and the Accelerated Vaccine Introduction initiative have worked to study rotavirus vaccines among developing-country populations to assist developing countries in introducing rotavirus vaccines into routine immunization programs. These partnerships are spearheaded by international non-governmental organization PATH, WHO, the U.S. Centers for Disease Control and Prevention, and the Global Alliance for Vaccines and Immunization.

Cost

The cost of rotavirus vaccination has fallen by 67 percent between 2006 and 2011 to USD 2.50 per dose, as part of an offer made by a pharmaceutical company to the GAVI Alliance. However, the vaccine is still more expensive than most other childhood vaccines included in the WHO's Expanded Programme on Immunization. India based Bharat Biotech sells Rotavac for $1 to governments in low-income countries.

The cost in developed countries, where it is not mandatory, can be however much higher. In France for example the vaccine is available to the public for EUR 60.38 (Jan 2016), fully at the user's charge.

The development of new vaccines intended to be offered at lower cost than the approved vaccines is ongoing. A vaccine from Sanofi affiliate Shantha Biotechnics is currently (2015) in Phase III clinical trials.

Temporary suspension

On March 22, 2010, the detection of DNA from porcine circovirus types 1 and 2 within RotaTeq and Rotarix prompted the FDA to suspend the use of rotavirus vaccines while conducting an investigation the finding of DNA from porcine circovirus-1 (PCV1) in the vaccine in collaboration with the 12 members of the Vaccines and Related Biological Products Advisory Committee (VRBPAC). On May 6, 2010, the FDA announced its decision to revoke the suspension, stating that porcine circovirus types 1 and 2 pose no safety risks in humans and concluded that health risks involved did not offset the benefits of the vaccination. In May 2010 the suspension of the Rotarix vaccine was lifted.

Research

Additional rotavirus vaccines are under development. These include: a human neonatal P[6]G3 strain, RV3, developed by Ruth Bishop and colleagues in Australia, a human bovine reassortant vaccine developed by Albert Kapikian and presently undergoing development and trials in different countries and a neonatal strain vaccine (G9P11) being developed by Bharat Biotech in India. This G9P(11) virus strain has the VP4 of bovine rotavirus origin, and all other segments of human rotavirus origin. Other approaches to the development of rotavirus vaccines are also being pursued. Rotavirus antigens for parenteral delivery have received some attention as virus-like particles prepared in baculovirus, expressed antigens, DNA vaccines, and killed virus. These novel approaches are being pursued using animal models.

External links

• National Clearinghouse Guideline: Prevention of rotavirus gastroenteritis among infants and children. Recommendations of the Advisory Committee on Immunization Practices (ACIP).
• PATH Rotavirus Vaccine Program
• Vaccine Information Statement from the US Centers for Disease Control and Prevention (as of December 1, 2007, available in English, Spanish, Somali, and Thai)
• Vaccine Resource Library: Rotavirus